A traditional model for delivering rear-time communication services to e.g. enterprises has been to install dedicated communication hardware and software within the enterprise premises. In this model, the enterprise purchases the communication infrastructure and deploys it within its own premises. The enterprise also takes care of the maintenance of its on-premises communication infrastructure.
Today, an increasing number of cloud-based providers offer their services to enterprise customers. The cloud providers are offering their equipment, in particular virtualized communication servers in their data centers, and also take care of maintaining the servers and cloud network on behalf of the enterprise customers.
There is a need for cloud-based hosted communication services since far from all enterprises can afford or want to invest time and resources in building their own on-premises communication solution. Instead, these enterprises want to outsource the complexity of maintaining the infrastructure required by the communication solution to a third party provider, that is, to the cloud service provider. A challenge that the cloud service provider faces is the running of a complex communication service and its components in its own cloud network for multiple enterprise customers in parallel.
The architectures of present-day real-time communication systems are highly complex. Typically, these solutions use a layered architecture dividing nodes involved in the communication system into media plane nodes and control plane nodes. The number of control plane nodes in particular can be very high. As an example, in the Third Generation Partnership Project (3GPP) IP (Internet Protocol) Multimedia Subsystem (IMS) architecture, there are several control plane nodes, including among others Call Session Control Functions (CSCF): Proxy CSCF (P-CSCF), Interrogating CSCF (I-CSCF), and Serving CSCF (S-CSCF); Media Resource Function Controllers (MRFCs), SIP (Session Initiation Protocol) Application Servers (ASs), and Session Border Controllers (SBCs). The MS architecture is perhaps the most extreme example, but in general, architectures of standardized communication systems are fairly complex.
For a cloud service provider that needs to host the full set of nodes required to deliver communication services in its cloud infrastructure for multiple enterprise customers in parallel, the situation is highly challenging. The resulting complexity, i.e. the need to run multiple virtualized control and media plane nodes in the datacenters and to manage the interconnections between these components, makes it more expensive to provide the communication service and also makes maintenance of the communication system more difficult. Thus, it is clear that cloud service providers would benefit from more simple and thus more cloud-friendly real-time communication system architectures.
In addition to cloud service providers, also enterprises running virtualized communication solutions in their private clouds could benefit from simpler communication service architectures.